This application relates to a mechanical linkage for driving a compressor inlet guide vane system for gas turbine engines, wherein a spring preload is included into the mechanical linkage.
Gas turbine engines include a compressor which compresses air and delivers it into a combustion section where it is mixed with fuel and burned. Products of this combustion pass downstream over a turbine section, driving turbine rotors to provide power to the gas turbine engine.
Inlet guide vanes typically control the flow of air to the compressor section. Variable vane systems are known. In such systems, an angle of incidence provided by the vanes, for guiding the air to the compressor, is varied depending upon the amount of air that is to be delivered to the compressor.
In one such system, a ring gear is driven to rotate through a mechanical linkage including a plurality of rods, and a hydraulic motor for driving the rods. The ring gear drives a plurality of sector gears to cause a plurality of vanes to rotate as the ring gear is driven to rotate between a full open and full closed position.
One challenge with these systems is that variables in the flow of air to the guide vanes, and the compressor, can cause vibration on the variable vanes, ring and sector gears, and across the mechanical linkage.